This application is based upon and claims the benefit of priority from the prior Japanese Patent Applications No. 11-332113, filed Nov. 22, 1999, and No. 2000-153509, filed May 24, 2000, the entire contents of which are incorporated herein by reference.
The present invention relates to an information provider system for pedestrian which shows a user a pedestrian route from an input departure place to an input destination and, more particularly, to an apparatus for automatically generating pedestrian route guide texts.
As portable route guidance systems for pedestrians, systems for displaying maps on the screens of terminals are available. Many of these systems allow users to freely scroll maps and walk to destinations while seeing the maps. Recently, apparatuses for automatically displaying map around the current positions by obtaining the current positions by using position information services provided through GPSs and PHSs have been commercially available.
Because of the use of image information, i.e., maps, however, it is difficult to use such systems in apparatuses having small screens, such as portable telephones and PHSs which have recently become very popular.
In many cases, users want to refer to route guide information while they are walking, and hence demands have arisen for the provision of information by voice in consideration of the safety of pedestrians. From this point of view, there are strong demands for conversion of route guide information into a language and texts. To convert route guide information into a language, a route must be searched out on the basis of general road network data issued by a map company and the like.
In these data, however, line segments of components different from actual roads, which are often present in portions where the road width is large and includes the entrances and exits of center traffic strips and elevated roads, are often included in searched routes. These line segments do not pose any serious problem in generating a simplified map for route guidance. In generating a route guide text on the basis of this route, however, such route information needs to be geometrically shaped. This editing processing leads to simplification of the route and a text to be generated. However, there has been no system which is designed to generate a route guide text by such editing processing.
As a technique of converting map information into a language, which has already been commercialized, a voice guidance function in a car navigation system is available. Many of such guidance data are formed on the basis of road names and crossing names, and hence are not suitable for guidance for pedestrians. Guidance for a pedestrian is preferably made on the basis of target objects such as buildings near these roads and crossings, i.e., landmark information. Several systems using such a technique have been proposed. Each of these systems presents landmark information by directly using landmark names. In practice, some buildings as target objects allow a pedestrian to specify their names as the pedestrian walks near the buildings, but other target objects allow the pedestrian to recognize only their types. For this reason, a method of expressing a landmark needs to be switched to an appropriate one in accordance with the type of landmark. However, such a system has not existed.
In addition, since landmark information changes day by day, information held by a system may differ from actual information. For example, some buildings may be demolished and the names of some stores may be changed. Furthermore, the surroundings of a given target object may change to make the object less noticeable. As a consequence, the object may become inadequate as a landmark. However, no conventional system can display another landmark located near such a landmark.
Pedestrian route guidance systems are strongly required to convert a route guide map into a language, i.e., generate a route guide text. In obtaining a route as a base for route guidance, however, the route is affected by line segments of components different from an actual road on a road network. For this reason, editing must be performed to remove these line segments from the obtained route. However, such a system has not existed.
There are also demands for a system designed to automatically switch expression methods in accordance with the types of landmarks to be presented. However, such a system has not existed. In some case, changes in landmarks themselves or surroundings make landmarks prepared by a system useless as guides. In consideration of such a case, a system that allows a user to freely call other landmarks is required. However, such a system has not existed.
It is an object of the present invention to provide an apparatus for automatically generating a pedestrian route guide text, which generates an accurate, simple route guide text without any influences of short line segments on a road network.
It is another object of the present invention to provide an apparatus for automatically generating a pedestrian route guide text, which generate a route guide text easy to understand for a pedestrian by switching expressions in accordance with landmarks.
It is still another object of the present invention to provide an apparatus for automatically generating a pedestrian route guide text, which can flexibly cope with changes in surroundings, e.g., a failure to find a landmark as a guide.
According to the present invention, there is provided an apparatus for automatically generating a pedestrian route guide text, comprising an input section which inputs a departure place and destination, a route data generator section which outputs route data, a landmark information generator section which outputs a landmark serving as a guide for a pedestrian and information associated with an expression form of the landmark, a route computation section which computes a route from the departure place to the destination, which are input through the input section, on the basis of route data obtained from the route data generator section, a route editing section which edits the route to remove a noise element that causes a guidance error from the route obtained by the route computation section, a landmark selector section which selects a landmark at each point on the route on the basis of the route obtained by the route editing section, a route guide text generator section which generates a route guide text on the basis of the route obtained by the route editing section and landmark information selected by the landmark selector section, and a route text output section which presents the route guide text generated by the route guide text generator section.
According to the present invention, the landmark selector section extracts a landmark within a predetermined distance range, and the route text output section, if a plurality of landmarks are extracted, presents at least one of the extracted landmarks.
According to the present invention, the route text output section presents the route guide text by using at least one of presentation using a landmark name and presentation using an expression representing a characteristic feature.
According to the present invention, if a straight path on a route exceeds a predetermined length, landmark information is selected midway along the straight path.
According to the present invention, the route guide text generator section generates a guide text by expressing a distance from a given point to a next point on a route using at least one of expressions of an absolute distance, a necessary time, and the number of necessary steps.
According to the present invention, the route guide text generator section expresses a distance or walking direction from a given point to a next point on a route upon rounding off within a range in which a pedestrian is not misled.
According to the present invention, the route guide text generator section emphasizes and presents a landmark name.
According to the present invention, the route guide text generator section presents a type of landmark with an icon being attached thereto.
According to the present invention, the route guide text generator section can present a route guide text upon deleting a portion thereof which corresponds to a place where the pedestrian has already walked.
In addition, according to the present invention, there is provided a method of automatically generating a pedestrian route guide text, comprising the steps of setting a departure place and destination, preparing route data, a landmark serving as a guide for a pedestrian, and landmark information associated with an expression form of the landmark, computing a route from the set departure place to the set destination on the basis of the route data, editing the route to remove a noise element that causes a guidance error from the route obtained by the computation, selecting a landmark at each point on the route on the basis of the edited route, generating a route guide text on the basis of the edited route and selected landmark information, and presenting the generated route guide text.
Furthermore, according to the present invention, there is provided a recording medium storing a program for causing a computer to function as a destination setting section which sets a departure place and destination, a landmark selecting section which acquire route data, a landmark serving as a guide for a pedestrian, and landmark information associated with an expression form of the landmark, a computation section which computes a route from the departure place to the destination on the basis of the route data, an editing section which edits the route to remove a noise element that causes a guidance error from the route obtained by the computation, a selector section which selects a landmark at each point on the route on the basis of the edited route, a route guide text generator section which generates a route guide text on the basis of the edited route and selected landmark information, and a route text output section which presents the generated route guide text.
According to the present invention, the apparatus further comprises a landmark list storage section and sequentially manages the landmarks obtained by the landmark selector section in the form of a list structure, starting from the first candidate.
According to the present invention, by changing the item of landmark IDs of route data into that of landmark list IDs, second and third landmarks can be extracted, as well as the first candidate, by tracing the list.
In addition, according to the present invention, a system is implemented, which includes a section which edits a searched route to reduce the influences of short line segments (garbage) on a road network and generate a simple, easy-to-understand route guide text.
According to the present invention, a system is implemented, in which information indicating how landmark information is expressed is added to the landmark information, and even if such information is not given, an appropriate expression method is selected in accordance with a landmark by setting a default value corresponding to each type of landmark, thereby generating a route guide text which is easy for a pedestrian to understand.
Furthermore, according to the present invention, a system is implemented, in which for each landmark selected by the system, other nearby landmarks are linked to the selected ones so as to allow the user to freely call these landmarks afterward, thereby flexibly coping with changes in surroundings.
According to the present invention, there is provided an apparatus for automatically generating a pedestrian route guide text, comprising an input section which inputs a departure place and destination, a route data storage section which stores route data, a landmark storage section which stores a landmark serving as a guide and information associated with an expression form of the landmark, a route computation section which computes a route from the departure place to the destination, which are input through the input section, on the basis of route data stored in the route data storage section, a route editing section which edits the route to remove a noise element that causes a guidance error from the route obtained by the route computation section, a landmark selector section which selects a landmark at each point on the route on the basis of the route obtained by the route computation section and the route editing section, a simplified map display landmark selector section which selects a landmark to be displayed on a simplified map from the selected landmarks, a simplified map drawing section which generates a simplified map for the route on the basis of the route obtained by the route computation section and the landmark information selected by the simplified map display landmark selector section, a route guide text generator section which generates a route guide text on the basis of the route obtained by the route computation section and the route editing section and the landmark information selected by the landmark selector section and the simplified map display landmark selector section, and a route text output section which presents the route guide text generated by the route guide text generator section and the simplified map generated by the simplified map drawing section.
Additional objects and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objects and advantages of the invention may be realized and obtained by means of the instrumentalities and combinations particularly pointed out hereinafter.